External Table Concept
Definition External tables allow Oracle to query data that is stored outside the database in flat files. Means it maybe a txt, excel file, .csv etc. The ORACLE_LOADER driver can be used to access any data stored in any format that can be loaded by SQL*Loader. Views and synonyms can be created against external tables. They are useful in the ETL process of data warehouses since the data doesn't need to be staged and can be queried in parallel. They should not be used for frequently queried tables. Prerequisite CREATE ANY DIRECTORY privilege require Create oracle directory to place your flat file Grant read write to that NOTE: In Oracle we can create external table two way Using Oracle Loader concept Using Oracle Datapump concept ORACLE_LOADER driver is the default. Il loads data from text-datafile only.It can not perform unload. ORACLE_DATAPUMP driver can perform both loads and unloads. It takes dump binary file as input and also has capability to unlo